Formula (I) includes pyrazolotriazole compounds which are useful as dye-forming .sup.1 H-pyrazolo[1,5-b][1,2,4]triazole couplers employed in color photographic silver halide materials, wherein R, R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 and X are as defined above. Similar couplers are described in Japanese Kokai 2-201,443, which is equivalent to European Patent application 381,183 and U.S. Pat. No. 5,066,575 (hereafter referred to as "Sato"). For example, Sato discloses couplers of the formula: ##STR5##
Sato further discloses a method of making such couplers. However, the disclosed process for preparing the couplers is complicated and entails considerable difficulties. Sato's scheme is as follows: ##STR6##
Sato's method is disadvantageous in that (1) the starting material (V) is not commercially available and its preparation requires a two-step process and (2) it is difficult to isolate the intermediate of formula (X) in a sufficiently pure form because this intermediate is always contaminated by a hydrazide of formula (XI), which is a by-product generated in the step of deblocking the intermediate of formula (IX). Consequently, the resulting amine of formula (X) is not sufficiently pure for the next step of the synthesis. Sato's process therefore requires a number of separation and purification steps.